In a patient who is unable to feed in the normal way via the mouth, a feeding tube is frequently used by doctors to convey nutrition directly to the stomach. When the tube enters the stomach through an aperture in the abdomen, it is called a gastrostomy feeding tube. The preferred technique to insert the tube in gastrostomy operations is the pull-method of percutaneous endoscopic gastrostomy (PEG pull-method).
In the PEG pull-method, a conical dilator with a wire loop at its tip is pulled through the tissues, creating a tunnel for the tube to pass.
Many steps are needed to manufacture the dilator as illustrated in FIG. 1. The first step is the crimping of a length of wire to form the loop at one end and two blunt ends at the other (FIG. 1A). Next, the body of the dilator is insert-molded around a portion of the crimped wire such that the crimped wire loop protrudes from the tip of the dilator and the blunt ends of the crimped wire protrude from the base of the dilator (FIG. 1C). This base is the portion of the dilator that is pushed into one end of the feeding tube. The base of the dilator is ribbed (or barbed) so that the dilator and tube do not separate easily. The third step involves trimming the ends of the blunt ends of the crimped wire protruding from the base of the dilator so they are more or less flush with the base (not shown).
The tube is then fitted over the base of the dilator until the edge of the tube is flush with the largest diameter of the conical portion of the dilator (FIG. 1D). If there is a gap, there is a risk of the end of the tube snagging on tissues. To make the joint more secure, a liquid adhesive is often injected to bond the tube and the dilator together as the final step (FIG. 1E). Alternatively, a sheath of specialty plastic is heat-shrunk over the joint. The manufacture of such a dilator is time consuming, labour intensive and expensive. Such dilators may also be difficult to assemble and use.
The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.
It is an object of this invention to provide a dilator and a method of manufacturing the same that ameliorates the problems of prior art dilators and current methods of manufacturing the same.